1. Field of the Invention
The present invention relates, in general, to an ortho-alkylation method of an aromatic ketone and, more particularly, to a method for introducing an alkyl moiety to an ortho-position of an aromatic ketone by reacting the ketones with olefins in the presence of an amine catalyst and a transition metal catalyst.
2. Description of Related Art
Until now, the introduction of substituents to aromatic compounds has been carried out depending on ortho and para-directivity of conventional substituents. However, it is difficult to introduce a new substituent to ortho-position of compounds because of their steric hindrance, as it is. Further, in a general organic synthesis, functional groups cannot be selectively attached to the ortho-position of aromatic compounds. Additionally, a Fridel-Craft alkylation of aromatic compounds has the same limitation as described above.
Ortho-alkylation through a homogeneous catalyst reaction was first studied by Professor S. Murai, Japan, wherein alkyl groups were introduced to ortho-position of aromatic ketones by reacting the ketones with a silane group-containing olefins in the presence of a ruthenium catalyst. However, this method suffers from the disadvantages of having high efficiency for only silane-containing olefins, and low efficiency or no reactivity for general alkyl moiety-containing olefins, internal olefins or diene compounds.